Rotary, earth trepanning tools



July 1, 1.959

L. R. MCGUIRE ROTARY, EARTH TREPANNING TOOLS 2 Sheets-Sham:` .i

Filed June 6, 1956 July 7, 1959 L. R. MCGUIRE ROTARY, EARTH TREPANNING TOOLS n 2 Sheets-Sheet 2 Filed June 6, 1956 INVENTO 'Y gif/*f ROTARY, EARTH TREPANNING TOOLS Lee R. McGuire, Newark, Del.

Application June 6, 1956, Serial No. 589,687

Claims. (Cl. Z55-72) This invention relates to the art of drilling oil wells or similar deep earthen holes, and more particularly to earth boring tools of a novel trepanning type. It has as its purpose a plurality of inter-related objectives not heretofore attainable by conventional rotary bits or coring tools.

Its use contemplates the availability of a high iluid pressure, preferably of an inert gaseous nature, to propel the cuttings and solid core earthen plugs from the hole bottom to the earths surface in a manner analogous to pneumatic tube conveying and the cleaning of long petroleum pipe lines by the uid pressure propulsion of elements known to the crude oil transportation arts under such varying names as plugs, pigs, go-devils, etc.

Among the objectives of this invention is the provision of: (a) A rotary, earth trepanning tool which may be dimensionally constricted to enable its passage through a long small diameter tubular metal well hole casing, and there-under be dirnensionally expanded in a manner which will enable it to bore a hole in the earth larger than the outside diameter of said casing. Thus enabling said earth hole protective casing to be moved progressively downward simultaneously with the downward progress of the hole, (b) to provide a maximum of protection against open (uncased) hole cave-ins, (c) to restrict the ilow of unwanted liquids into the bored hole, (d) to eliminate the need for the conventional costly programs of utilizing a series of successively smaller diameter casings, one within the other, as is mandatory with deep holes bored by the use of fixed diameter boring tools, (e) to provide an earth trepanning tool including a plurality of cutting stages one above the other disposed in a manner whereby the resulting core may be progressively reduced in diameter to a predetermined size for iluid pressure transportation to the earths surface, thereby providing continuous solid core samples for geological and physical examination, (f) to provide an earth hole boring tool whereby a maximum of cutting edge length may be included in a tool of given diameter, thereby reducing the frequency and duration of time lost and money expended for the changing of tools which operation necessitates a withdrawal of the tool to the earths surface, (g) to provide an earth hole boring tool including features whereby all earth cutting elements are within the protective confines of a rugged tool body during transit through the surrounding metal well hole casing. Such holes commonly deviate from a true vertical position and as a consequence disruptive impacts between casing walls and conventional boring tools with exposed cutting elements frequently results in substantial damage in the form of crushed or loosened diamonds in case of diamond drills, or the breaking off of teeth from the more conventional rotary cone type bits.

` nited States arent O Further objects and advantages of the present inven- Fig. 2 is a sectional elevation of the tool in working position as taken along line 2--2 of Figure 1.

Fig. 3 is a fragmentary section taken along line 3-3 of Figure 2.

Fig. 4 is a fragmentary sectional elevation showing the core forming cutters in a fully retracted position.

Fig. 5 is an enlarged sectional plan view along line 5-5 of Figure 2 showing the lower stage cutters in a fully extended or normal working position.

Fig. 6 is an enlarged sectional plan View along line 6--6 of Figure 2.

Fig. 7 is an enlarged sectional plan view along line 7-7 of Figure 2 or center line of the core trimming cutters.

Fig. 8 is an enlarged sectional plan view along line 8 8 of Figure 2.

Figure 9 is an enlarged sectional plan view along line 9-9 of Figure 4.

In the following description of the drawings, like numbers indicate like parts in the various views.

Fig. 1 shows tool body 10 positioned at the earth hole bottom in boring position. Body 10 is a rugged tubular member having a pentagon shaped interior 11, it being concentrically disposed inside of tubular metal well hole protective casing 12 and round earthen hole 13 as is more clearly shown in Figure 2.

Fig. 2, indicates body member 10 to be threaded at its upper end 14 for rigid attachment to the lower end of shaft 15 (dotted) which is a source of relatively high speed rotative power from means not encompassed by this invention. The bottom end of body 10 contains a plurality of axially extending milled slots 16 between which are body fingers 10a. These slots 16 provide a close sliding iit for retractable lever 20 to insure against vibration of the core forming assemblies. Each of these assemblies includes a circular rotatively mounted tungsten-carbide earth cutting element 17 of disk shape mounted on a concentric flanged bearing bushing 18 which is rotatively positioned on stub shaft 19. One end of this shaft 19 is press-lit into retractable lever 20 near its lower end. These retractable levers 20 are iirmly secured to tool body 1t) by means of hinge pins 21. The upper end surface of levers 20 includes a cam shaped contour 22 which functions in conjunction with the top surface of slots 16 to limit the angular movement of levers 2li in a manner to fix the maximum inside diameter of earth hole bore 13 and the minimum outside diameter of earth core 23 for any given diameter of cutters 17. These core forming or earth cutting elements 17 are caused to rotate about their own axis as a consequence of an oblique force acting thereon during the earth trepanning operation, as will be more clearly understood by reference to Fig. 5, which shows retractable cutters 17 in a fully extended or working position. When tool body 10 with projecting fingers 10a is rotated about core 23 in the direction of arrow 30, the leading face and cutting edge of cutters 17 as shown in Figure 5 is parallel to and slightly in advance of true radial line 31 and consequently the earth shearing forces will be presented against the face of cutter 17 at an oblique angle 32. It is these obliquely applied forces which slowly rotates cutters 17 in the direction indicated by arrow 33 of Figure 2; thus providing for the utilization of the entire periphery of cutters 17 for earth shearing and insuring a minimum need for cutter replacements due to abrasive wear which is an item of large expense with conventional tools when boring at great depths.

With further reference to Fig. 2: As trepanning tool body 10 with its appended parts progresses downward in the earth, a central core 23 is produced and the top of this core is brought into cutting'engagement with a plurality of core trimming circular rotatively mounted tungsten-carbide cutting elements 25 of disk shape. Each of said elements is provided with a central hanged bushing 26 and positioned on removable shafts or pins 27.

.As tool body and its appended parts is. caused to move progressively downward .into .the earth as a kconsequence of rotation in vthe direction of arrow 30, the core 23 as produced by retractable cutters 17 will vbe reduced to a smaller diameter on contacting non-retractable cutting elements 25. The plurality of cutting elements 25 will be caused to rotate Aon their own axis as a result of frictional contact with core 23 as it moves relatively upward inside of the-downwardly moving tool body 10. As a consequence of cutters 25 being so rotated on their own axis, the entire circumference thereof will be successively utilized in reducing the diameter .0f core 23 with resulting longer periods between the need for changing worn cutting elements than could be attained -in .the same space with non-rotating cutters.

With further reference to Fig. 2: Above the plurality ofy core trimming cutting elements 25 is :positioned a single roller 28 of hard abrasive resisting material. This roller is Vrotatively positioned in tool body 10, and has as its function the periodical transverse bisecting of rcduced diameter earthen core 23 into a series of cylin- .dr-ical plugs .24. As tool body 10 with -its appended parts is caused to progress downward into the earth, roller 28 engages the top of core 23 causing it to be deliected from its normally central position as it is forced past roller 28. This deiiection produces a cantilever type bending moment at a point along dotted line 29 or at an intermediate weaker cross-section. Since roller 28 is a fixed -part appended to tool body 10 it is both rotated about the -vertical axis of core 23 and about its own longitudinal axis as a consequence of frictional contact with upwardly advancing core 23. In so rotating roller 28 will imparta wobbling motion to said core top with attendant rapid reversals in the bending stress at or near critical section line 29 which will produce periodical transverse bisecting of the upwardly advancing core 23 of reduced diameter. This bisecting produces plugs 24 which are then free to move past roller .28 in a position slightly eccentric with respect to the normal center of remaining larger core 23 and the rotative axis of tool body 10. This core transverse bisecting being a cyclic occurrence each time an unbroken portion of solid earthen core 23 upwardly advances into contact with roller 28. -For an earthen core 23 of uniform physical strength the length of plugs 24 as broken, -will be approximately equal to the distance vbetween cutters 25 and roller 28. As plugs 24 successively move upwardpast roller 23, said roller is caused to rotate on its own central axis, thereby distributing frictional wear over a wide peripheral area to insure a maximum duration of working period before the need of replacements due to wear.

With further reference to Fig. 2: In the trepanning operation as above described, the cutting elements 17 and 25 produce a substantial volume of relatively small earthen particles as cuttings or mud which must be delivered from the hole bottom to the earths surface as the bore is deepened. This invention is predicated on the availability of a high-pressure, high-velocity uid means to accomplish the above mentioned delivery. Said fluid stream is directed to the earth hole bottom through the annular space 34 existing between tool body 10 and the inner wall of tubular metal casing 12, then through annular space 3S and passing under the lower end of tool body 1t) and upward in the open pentagon lshaped interior 11 of tool body 10 surrounding core 23 in a manner known to the art-as reverse circulation. In so passing the high velocity uid stream carries with it to the earths Vsurface all cuttings produced Aby cutting elements .17 and 25 by upward passage through tubular shaft (dotted) and an additional :tubular `conveyor 4 channel not encompassed by this invention. The highpressure fluid stream also delivers the solid earthen core plugs 24 as they are periodically freed by core breaking roller 28 under conditions previously described. These plugs 24 are only slightly less in diameter than the inside diameter of tubular conveyor extending upward to the earth surface, hence will obstruct the free ow of the upwardly moving iluid stream, and as a consequence of the high fluid pressure thereunder said plugs 24 will be caused to move upward at high velocity and in so doing will act to clear the above described tubular conveyor channel of all earth hole cuttings or liquids interposed between the tops of said plugs 24 and the upper terminal of the conVeyOrchannel. Fig. 3 is a fragmentary sectional view along line 3 3 of Figure 2. That more clearly indicates the manner in which the retractable core forming cutting elements 17 and associated parts 1S, 19 and 20 are slidably interposed in axially `extending milled slots 16 between the plurality of downwardly extending tool body fingers 10a to provide strength and rigidity to the retractable parts assembly and to prevent chattering during operation, of the tool in hard earth formations. This View ,also indicates more fully the manner in which pin 21 is disposed in tool body .10.

Fig. 4 shows body 10 with its associated components in a position emerging from the lower end of earth hole protective metal casing 12 and with core forming cutters 17 in a fully retracted position, as determined by cam contour 22 on the upper end surface of lever 20. From the position shown, as tool body 10 with its associated parts is moved further downward, the circular core forming or cutting elements 17 will contact the top ot' stationary core 23 at a position below the end of casing 12 and as a consequence core forming cutters 17 will be caused to move outward into dotted positions 36 which .constitute theirnormal working position on reaching the hole bottom as shown in Figure 2;

Figure 5 is an enlarged sectional view along line S-.S of Figure 2 disclosing a plurality of core forming cutting elements `-17 and associated parts 18, 19 and 2t), all of which are retractably positioned in Vslots 16 at the lower end of tool body 10 and interposed between the downward extending fingers 10a Yas previously described. As indicated the complete assembly is in normal working position at the bottom of earth hole 13 and subject to rotation in the direction of arrow 30.

Figure 6 is an enlarged sectional .View showing a plurality offlike hinge pins 21, each positioned in reamed holes included in body 10 in a manner whereby pins 21 are locked by end abutment, one against the other. One of said pins 21 is provided with a beveled end 42 which has vbeen drilled to receive spring pin 43. This spring pin serves to lock the entire series of pins '21 within the periphery of tool body 10 in a manner whereby retractable levers 20 may be quickly detached for replacement of dulled core forming cutters 17, this being accomplished byiirst removing 'spring pin 43 as indicated by dotted lines 44 after'which the adjacent hinge pin 21 is removed as indicated by dotted line 45, thereby freeing the entire series of pins 21, and enabling quick detachment of one or more retractable levers 2 0, and when so detached core forming cutters k17 will be readily removablelfrom stub shafts 19.

Fig. 7 is an enlarged view showing a plurality of like .core trimming cutter shafts V27 positioned in a manner hole of body as set forth in describing Figure 2. Core 23 is shown positioned within the pentagon shaped interior walls 11 of tool body 10. As said core 23 moved relatively upward into contact with circular roller 28 it is caused to deflect as indicated by dot-dash lines 52, and since core transverse bisecting roller 28 is flxedly positioned in tool body 10 it rotates therewith in a manner to produce a wobbling movement of the core 23 which results in core 23 being bisected as described in connection with Figure 2. Roller 28 is retained in its normal working position by spring pin 50 as driven into a drilled hole in tool body 10. Removal of spring pin 50 as indicated by dotted lines 51 permits the easy replacement of roller 28 as may be infrequently required due to abrasive wear.

Fig. 9 is an enlarged view along line 9-9 of Figure 4 and shows the core forming cutter assemblies consisting,

of parts 17, 18, 19 and 20 in a fully retracted position lbetween the plurality of downwardly extending ibody fingers 10a and within the protective confines of tool body 10 outer periphery. Said assemblies are held in this fully retracted position during transit through tubular casing 12 by means of a plurality of ball detent facilities wherein the small end of shaft 19 contains an indentation 37 into which is forced a hardened metal ball 38 by reason of compression spring 39 within a drilled hole 40 in each body iinger 10a. 'Dhese parts 38 and 39 are retained in hole 40 by means of tightly fitted plug 41.

Prom the above description and drawings it will 'be apparent to persons skilled in the art that the most desired number of core forming cutters 17 may vary with the diameter of the earth hole to be produced and the diameter of the cutters utilized, also it will be apparent the number and size of the core trimming cutters may be varied to produce a linal core diameter of any predetermined smaller size, or that the number of core trimming cutters utilized for core size reduction may be varied to provide greater or less total length of cutter periphery for a given core diameter.

Changes and modifications in the specification hereof may be made without departing from the scope of the invention as encompassed within the following claims, wherein I claim:

1. A rotary, earth trepanning tool including a tubular body with a plurality of `elongated slots extending upward from is lower end through the wall of said lbody between rigid body fingers, a hinge pin extending across each slot with its ends bearing within the adjacent 4body fingers, a retractive lever slidably positioned in each of said slots with its upper end pivoted on a hinge pin and its free end swingable in an arcuate path inward and outward from the longitudinal axis of the tubular body, a spring actuated ball detent recessed within each body finger with the detent partially movable into the slot, a concave indentation positioned near the free end of each retractive lever to engage the detent when said lever is at its inner position, a stub shaft rigidly secured near the free end of each retractive lever with its longitudinal 6 axis at right angles to the plane in which said lever is retractable, and a core forming cutter of circular disk shape axially positioned on each stub shaft with its peripheral cutting edge extending below all other components of the assembly to form a cylindrical earthen core within the tubular body.

2. In combination with a rotary, earth trepanning tool as set forth in claim 1, a circular disk shaped core forming cutter axially positioned on each stub shaft with its peripheral cutting edge oriented at an oblique angle with relation to a straight line extending radially from the longitudinal axis of the tubular body and interesecting said peripheral cutting edge at a point nearest to said longitudinal axis.

3. In combination with a rotary, earth trepanning tool, as set forth in claim 1, a core bisecting roller axially extending traversely across and Within the outer circumference of the tubular body with its ends bearing on the walls of the tubular body at a position above the core forming cutters, and with the peripheral surface of said core bisecting roller projecting inwardly towards the longitudinal axis of the tubular body to engage the cylindrical earthen core with sufficient lateral force to periodically bisect said core as the tool rotatively progresses into the earth.

4. In combination with a rotary, earth trepanning tool as set forth in claim 3, an extraneously supplied fluid stream flowing downward in the annular channel surrounding the tool body, thence directionally reversing to ow under the tool lbody and upward within the flow channel provided between the tool body interior and the cylindrical earthen core, with said iiuid stream simultaneously collecting and upwardly conveying all loosened earthen material beyond the interior of the tubular tool body.

5. A rotary, earth trepanning tool including a tubular body, a plurality of slots separately spaced around the circumference of said body and extending radially through the wall thereof, a removable shaft extending across each slot with its ends bearing in said tubular wall, a circular disk shaped cutter axially positioned on each shaft with its periphery lboth within the tool body and inwardly projecting to trim a central earthen core as the tool rotatively progresses downward into the earth.

References Cited in the iile of this patent UNITED STATES PATENTS 1,133,161 McAllister Mar. 23, 1915 1,306,674 Esseling June 10, 1919 1,571,309 Wall Feb. 2, 1926 1,836,638 Wright et al Dec. 15, 1931 2,034,072 Wright Mar. 17, 1936 2,122,863 Howard et al. July 5, 1938 2,174,587 Love Oct. 3, 1939 2,495,509 Cressey Jan. 24, 1950 2,549,420 Camp Apr. 17, 1951 2,586,878 Staton Feb. 26, 1952 

